Combined ski boot and binding

ABSTRACT

A combined ski boot and binding giving improved protection from leg breakages includes a two part boot having an ankle cuff portion pivotal about a base portion, and a releasable rear binding which directly connects the ankle cuff portion and the ski. The rear binding releases not only in response to a forwards pivotal force applied to the whole boot, as in conventional safety release bindings, but also, at least partly, in response to pivotal movement between the ankle cuff portion and the base portion of the boot. Another feature of the invention is a toe binding comprising a support pivotal about an axis normal to the ski, the support carrying two laterally spaced spring biased plungers, the ends of which engage in recesses in the toe of the boot, so that release of the toe can occur by simultaneously sideways swiveling of the boot and the support.

United States Patent 1191 Davis 1451 Mar. 11, 1975 22 Filed:

1 1 COMBINED SKI BOOT AND BINDING Jan. 29, 1973 [21] Appl. N0.: 327,432

[52] US. Cl. 280/1l.35 N, 36/2.5 AL, 280/11.35 R [51] Int. Cl. A63c9/086 [58] Field of Search280/1 1.35 R, 11.35 T, 11.35 N,

280/11.35 K, 11.35 C, 11.35 Y; 36/25 AL [56] References Cited UNITEDSTATES PATENTS 2,669,459 2/1954 Fleming 280/11 35 R 3,160,421 12/1964Bugg 280/11 35 K 3,511,516 5/1970 Smolka ct a]. 280/1 1.35 C 3,753.5718/1973 Gcrtsch ct a1 280/1 1.35 K 3.781.028 12/1973 Gcrtsch ct al 280/11.35 K

FOREIGN PATENTS OR APPLICATIONS 1,912,950 9/1970 Germany 280/1 1.35 N

Primary Etaminer-David Schonberg Assistant Examiner-David M. MitchellAttorney, Agent, or Firm-Cushman, Darby and Cushman 57 ABSTRACT Acombined ski boot and binding giving improved protection from legbreakages includes a two part boot having an ankle cuff portion pivotalabout a base portion, and a releasable rear binding which directlyconnects the ankle cuff portion and the ski. The rear binding releasesnot only in response to a forwards pivotal force applied to the wholeboot, as in conventional safety release bindings, but also, at leastpartly, in response to pivotal movement between the ankle cuff portionand the base portion of the boot. Another feature of the invention is atoe binding comprising a support pivotal about an axis normal to theski, the support carrying two laterally spaced spring biased plungers,the ends of which engage in recesses in the toe of the boot, so thatrelease of the toe can occur by simultaneously sideways swiveling of theboot and the support.

12 Claims, 8 Drawing Figures VPATENTEDHARI 1 1915- 3. 70325 sum 1 or 4PATENTEU H975 Q I 3,870,325

FIGS

COMBINED SKI BOOT AND BINDING I The present invention relates to a skiboot andbinding arrangement designed to give greater protection againstinjury in certain types of falls than that given by known safety releasebindings.

One feature of the invention is the rear binding means, which protectthe skier from leg injuries in a forward fall particularly whendownwards pressure is applied to the ski.

Conventional modern safety release rear bindings for ski boots include aclamping device which grips a rearwards lug or other projection on theheal of the boot, the clamping device being arranged to release in theevent of excessive upwards force being applied by the heel of the booton the binding. Such excessive forces may occur either by the skierfalling forwards while the skis remain on the snow, so that the boot(which is very stiff) is caused to pivot forwardly about the toe, or bya direct pull of the boot from the ski, or by combinations of thesemovements. Heel bindings of this kind must of course be combined withtoe bindings which permit the various movements of the boot giving theheel release. A typical modern safety release heel binding is shown inU.S. Pat. No. 3,556,543 which issued on Jan. 19, 1971 to Dovre SkiBinding Inc.

These conventional bindings have their drawback in that they allow legfractures to occur in certain situations, particularly where a skierfalls forward at the same time as he is applying strong downwardspressure to the skis, for example on bottoming after passing over abump, or on the landing after a jump. In such cases, the downwardspressure on the boot as a whole counteracts the upperwards force on theheel binding caused by the forwards fall, so that the heel does notnecessarily release. The leg may thus be subject to excessive forces,causing fracture, without release of the heel. When the skier is wearinghigh rigid boots, as nowadays preferred by good skiers, accidents ofthis kind are likely to cause fracture of the fibula in the leg, whichis regarded as a serious injury.

The present invention has as one object to provide a combined ski bootand binding which will reduce injuries particularly of the serious typedescribed above.

The present invention is not merely concerned with a new type ofbinding, but the combination of this with a boot which forms an integralpart of the invention. The boot includes a base portion and an anklecuff portion pivotal on the base portion about a transverse axis, whichaxis is preferably coincident with the skiers ankle joint. The bindingincludes a front or toe binding for releasably holding the toe of thebase portion of the boot, and a rear binding for holding the heel of theboot against the ski, the rear binding including means for releasing theheel in response both to pivotal movement of the boot as a whole aboutthe toe through a predetermined abnormal angle, and to pivoting of thebase portion of the boot about the toe through an angle smaller thanthis predetermined angle when combined with forwarding pivoting of theankle cuff portion relative to the base portion about the pivotal axis.

This arrangement is believed to be unique in taking account of thepivoting of an ankle cuff portion about a pivotal axis roughlycoincident with a skiers ankle joint, to cause release of the boot whenthis amount of pivoting, taken in combination with pivoting about thetoe, corresponds to an excessive bending moment on the leg. Furthermore,the rear binding includes resilient means acting between the ankle cuffportion and the ski, said resilient means being arranged to allowlimited forward pivoting of the ankle cuff portion while increasing therelease forces on the rear binding but allowing the base portion toremain in firm contact with the ski. This ensures that the releaseangles referred to above correspond to predetermined bending moments onthe leg.

Preferably, the rear binding includes releasable connecting meansdirectly connecting the ski and a part of the ankle cuff portion behindthe pivotal axis thereof. the releasable connecting means beingsufficiently extendible to allow some forward pivotal movement of thecuff portion about this transverse axis during skiing. and sufficientlyresistant to extension to hold the ski in normal skiing position on theboot during skiing, the releasable connecting means being capable ofrelease when excessive force is applied thereto.

The rear binding may also yieldably restrain pivota movement of theankle cuff portion, so that the skier can lean forwards or backwardsagainst a spring force which urges the ankle cuff portion into a neutralposition. For this purpose, the said part of the ankle cuff portionbehind the pivotal axis thereof includes means projectng rearwardly fromthe ankle cuff portion and defining a slideway extending generally tothe longitudinal axis of the cuff portion, and the releasable connectingmeans includes the combination of:

l. releasable retaining means adapted to be permanently attached to theski, and

2. deformable connecting means comprising in combination a rod havingmeans at its lower end capable of being retained in said retaining meansand having a shaft portion slidable in said slideway and spring meansrestraining downwards movement of said rod relative to said cuffportion. The rod is flexible to allow limited resiliently restrainedpivoting of the cuff portion about its transverse pivotal axis, thespring means being sufficiently stiff normally to retain the heel of theboot on the ski in normal skiing position. The rod may be bent bothforwards and backwards from the neutral position which represents thenormal optimum skiing angle for the ankle cuff portion.

Boots formed of two parts, namely a base portion and an ankle cuffportion pivotal on the base portion, are known, for example fromCanadian Pat. No. 889,586 issued Jan. 4, 1972 to Caporicci. However, thebindings used with boots of this type have previously been ofconventional type which merely connects the base portion of the boot tothe ski, and which do not give any release effect caused by pivoting ofthe ankle cuff portion relative to the base portion.

It is also well known to have safety straps which directly connect theski to the ankle portion of a boot (for example, see U.S. Pat. No.2,491,485 to Durham issued Dec. 20, 1949). However, these straps havebeen used only as an auxiliary to the main binding, merely intended toprevent loss of the ski after the main binding has released. A safetystrap of this kind is fairly loose and/or readily extensible, and wouldnot be subject to any kind of excessive tension until the boot has beenreleased by the main binding.

Another feature of this invention is an improved front or toe binding,particularly suitable for use with the heel binding described, but alsousable with conventional heel bindings.

The improved toe binding is a modification of a type of binding known asthe Gertsch binding. In the Gertsch binding, a support is solidly fixedto the ski in front of the toe portion of a boot, this support carryinga single spring loaded plunger having a projecting rounded end whichengages a recess in a toe plate attached to the toe of the boot. The toebinding is used with a heel binding which locates the heel firmly andprevents rearwards movement of the boot, and the projecting end of thespring loaded plunger engages the recess to maintain the toe in place innormal skiing. The recess in the toe plate is shaped so that if the bootis subjected to excessive swiveling force about the axis of the skiersleg, or to an excessive upwards pull on the toe, the plunger will beforced back against its spring and the toe will release. This type oftoe binding has the drawback that it is likely to release not only whena skier falls, but also when the binding is subjected to shock loads forexample, caused by the ski passing over ruts or running at high speeds.Release of the ski caused by such shock loads is undesirable as it maycause the skier to fall and injure himself.

In the modification of the Gertsch binding provided for by thisinvention, the support has two parallel bores carrying two spring loadedplungers which engage in two laterally spaced recesses in the toe of theboot. Also, the support, instead of being fixed, is made pivotal about avertical axis (i.e., an axis normal to the top surface of the ski), thisvertical axis being situated between the two plungers. The plungers areaxially displacable by an amount sufficient to allow the boot to releaseby simultaneous sideways swiveling movement of the boot and of thesupport beyond a position in which the projecting end of a plunger liesdirectly between the vertical axis of the pivot and the locating meansfor the heel. The binding also preferably releases by upwards pull onthe toe.

This new toe binding permits some sideways movement of the toe withoutrelease of the binding, so that release is not likely to occur under theinfluence of shock loads such as would not cause the skier to fall.Also, the use of two laterally spaced plungers allows the ski to be heldfirmly onto the boot so that when the ski is edged the ski and bootrotate as one.

In order that the invention may be properly understood, a preferredembodiment thereof is shown in the accompanying drawings, in which:

FIG. 1 is a side view of a combined ski binding and boot;

FIG. 2 is an enlarged side view of part of the rear binding;

FIG. 3 is a plan view of part of the rear binding on section line 33 ofFIG. 2, and shown with locking means removed,

FIGS. 3a and 3b are respectively a top plan view and a rear view oflocking means for the rear binding;

FIG. 4 is a detailed side view of the ankle cuff portion of the boot,showing another part of the rear binding;

FIG. 5 is a detailed side view of the toe binding, and

FIG. 6 is a detailed plan view of the toe binding.

Referring to FIG. 1, a portion ofa ski 10 is shown on which is mounted atoe binding 12 and part of a heel binding 14. The area of skiintermediate the toe and heel binding preferably has one or more raisedplates such as plate 18 of FIG. 5 for receiving the sole of the boot.

The boot 16 comprises a base portion 20 which extends tojust above theankle joint of a skier, and which is formed by moulding plastic materialunder or over a metal reinforcing insert 21, which extends up the ankleat both sides of the boot. The base portion has the conventional openingwith buckles 23. The upper ends of insert 21 provide bearings for pivots24 carrying an ankle cuff portion 26, which is of relatively rigid plastics material and which has a front opening closed by buckle 27. Thetransverse pivotal axis formed by bindings 24 is approximatelycoincident with the ankle joint of a skier, so that the boot permitsrelatively free for wards pivoting of the ankle but braces the anklefirmly against sideways twisting when the skier is attempting to edgethe skis. The ankle cuff portion 26 has a rear upwards extension 26awhich reaches a height about the pivots 24 greater than the height ofthese pivots above the sole of the boot.

The ankle cuff portion 26, shown in more detail in FIG. 4, has spacedupper and lower extensions 30 and 31 projecting rearwardly thereof. Theupper extension 30 is near the upper end of extension 260. and the lowerextension 31 is in the same axial position along the cuff portion as arethe pivots 24. Upper extension 30 is integral with the plastics materialof the cuff portion, and lower extension 31 is part of a metal yokemember 33 having arms which extend partly around the inside surface ofthe ankle cuff portion, the ends of the arms having bearings engagingwith the pivots 24. The yoke member 33 is very rigidly attached to theankle cuff portion. v

The upper and lower extensions 30 and 31 each define a bore extendinggenerally parallel to the longitudinal axis of the cuff portion, thesebores being aligned with each other. These bores together form aslideway for the shaft portion 35 of a slightly flexible steel rod 36.The top end of the rod is a close fit in extension 30, and an air holemay be provided communicating with the top end of the bore in thisextension to allow for movement of air into and out of the bore as therod moves upwards and downwards in the lower part of the bore. The partof shaft portion 35 slidable in extension 31 is non-circular in section,as is the bore in extension 31, so that the rod 36 is prevented fromrotating out of the position shown.

The downwards movement of the rod 36 relative to the ankle cuff portionis restricted by a stiff compression spring 38 retained between theupper side of extension 31 and a stop member 39 adjustably mounted onthe shaft portion 35. The ends of the coil spring 38 engage in theextension 31 and in the stop member 39, so that both tension andcompression can be applied to the spring. The combination of rod 36,spring 38 and stop member 39 form extendible connecting means betweenthe fixed point on the ankle cuff portion constituted by extension 31,and releasable retaining means indicated at 14b which will be describedbelow.

The portion 41 of rod 36 below extension 31 is thicker than the shaftportion 35 and is bent outwardly from the heel of the boot, andterminates in a flattened end portion 43 (shown in detail in FIGS. 2 and3) which is bent inwardly so as to be approximately normal to the ski.At the top of the portion 43 the rod is provided with a ball member 45,which actually takes the form of a hemi-spherical projection on one sideof the flattened portion 43, as shown in FIG. 3. The ball member 45 andthe flat portion 43 cooperate with the releasable retaining means 14b tobe described.

The releasable retaining means 14b is shown in detail in FIGS. 2, 3, 3a,and 3b. These retaining means include a base plate 50 adapted to bepermanently attached to the ski 10, and a rigid upstanding plate 51 castintegrally with the base plate and having an upwardly projecting portion51a. The forward end of plate 51 is thickened as at 52, and the frontface of this is provided with a ridge 53 having a nearly verticalportion 52a extending upwardly from the ski, and which provides locatingmeans for a cleft 21a in the heel of the boot and which preciselypositions the boot in fore and aft position. Above the portion 52a is arearwardly curved portion 53b against which the heel can slide when theboot is being placed in the binding. To the rear of plate 51 is hingedat 54 a spring clip 55 also having an upwardly projecting portion 55adisposed in opposition to projecting portion 51a when the clip is in theclosed position shown, i.e., parallel to plate 51. The clip 55 can beheld in this closed position by a locking member 58 mounted on ahorizontal pivot carried by an upstanding lug 59 connected to plate 51near the hinge 54. The locking member 58, which is omitted from FIG. 3for clarity, is shown separately in FIGS. 3a and 3b. This locking memberincludes two opposed side plates 58a and 58b defining a recess whichreceives the outer surfaces of plate 51 and clip 55 to hold the clip inclosed position parallel to the plate 51. Plate 58a is vertical andslides over plate 51, while plate 58b flares outwardly as shown in FIG.3b. The plate 58b has an inner swelling 58c which snaps over anoutwardly turned lip 56 on the top of clip 55 when the locking member isin the locking position shown in FIG. 2, maintaining the locking memberin this position. The member 58 also has horizontal flanges 60 providingfor easy manipulation, these flanges having holes 60a sized to receivethe tip of a ski pole.

The projecting portion 55a of the clip has an enlarged head 62 carryingan insert 63 having a recess facing inwardly and shaped to receive theprojecting part of the ball member 45. The insert 63 is of Tef- Ion,this being a registered trade mark for polytetrafluoroethylene. Thearrangement is such that with locking member 58 in the raised position,the clip 55 can be hinged away from plate 51 so that the lower portion43 of rod 36 can be inserted or removed from between the projections 51aand 55a, and with the locking member 58 in the closed position of FIG. 2this holds the clip 55 in place and retains the ball member in thesocket member formed by the combination of plate 51 and clip 55. Theclip 55 is slightly flexible, and in addition the insert 63 is slightlyresilient, so that the ball member can be pulled from the socket member,without movement of the locking member 58, when extreme tension or otherforces are applied to rod 36, under conditions described below.

It may be noted that the inside faces of parts 51 and 55 provide opposedsurfaces facing opposite sides of the ski, which engage with the sidesof rod portion 43 to limit sideways angular movement of the rod relativeto the ski.

Also integral with plate 51 is an upstanding projection or horn 66having a sloped, rearward facing surface 66a situated below and slightlyforward of the socket member described. In the normal skiing position ofrod 36 this surface 66a is spaced just in front of the front bottomcorner of end portion 43 of rod 36, by an amount such that if the skierleans backward by.,an undue amount, e.g., such 'as to release the toe ofthe boot from the toe binding, pivoting of rod 36 about the socketmember causes portion 43 to contact surface 660. Further backwardpivoting from this position causes the ball member to be forced out ofthe socket member, releasing the heel binding.

FIGS. 5 and 6 show in detail the toe binding. 12. This comprises amounting lOO adapted to be permanently attached to the ski 10 by screwsand providing a mount for a vertical pivot pin 102 which carries asupport 101 and which allows rotation of the support about a verticalaxis (i.e., an axis normal to the ski). The support has two cylindricalportions defining two paralle bores spaced apart on opposite sides ofthe pivot pin 102, both of the cylindrical portions 104 being at thesame height above the top of the ski. In the operative position shown,the cylindrical portions 104 are both parallel to and spacedsymmetrically on opposite sides of the center line of the ski, whichcenter line also passes through the center ofthe locating means for theheel of the boot constituted by the ridge 53. The support 101 isreleasably retained in this aligned position by spring means which arenot shown.

Each of the bores of the cylindrical portions 104 carries a springloaded plunger having a rounded projecting end 106. The forward end ofeach of the springs biasing the plungers (i.e., the ends of the springsremote from the boot) is retained in place by a screw provided with anadjustment knob 108. Between knob 108 and the forward end of the portion104 are positioned spacers 110, the number of which can be varied toalter the compression of the springs acting on the plungers. Theprojecting ends 106 of the plungers engage in two laterally spacedforwards facing recesses or depressions 112 in the front, toe end of thesole of the boot. The recesses are shaped in side and plan view asindicated in FIGS. 5 and 6, and generally have a concave curvature ofradius slightly larger than the rounded ends of the plungers. The lowerlands of the recesses are slightly cut away, and slope downwardly fromthe bottom of the recess at an angle of roughly 45.

The plungers are axially displaceable against their springs by an amountsufficient to release the toe binding in two different ways. Firstly, ifthe boot is subjected to a rearwards pivoting about the heel, or verystrong upwards forces away from the ski, then the plungers will bedepressed sufficiently against their springs to clear the lower lands ofthe recesses and allow release of the toe of the boot. Secondly, theplungers can be displaced sufficiently to allow the boot to release bysimultaneous sideways swiveling of the boot (about the axis of theskiers leg) and swiveling of the support 101 about pivot 102 beyond aposition in which the projecting end of a plunger lies directly betweenthe pin 102 and the center of the heel locating means constituted byridge 53, i.e., beyond the position where the end of the plunger is onthe center line of the ski. This constitutes a dead center" position,and the boot toe can move sideways up to this position and still bereturned to the normal skiing position by the restoring forces of thespring acting on the plungers. For this reason, this toe binding is notreadily caused to release under shock loads, as happens with the knownGertsch binding. As mentioned, spring means within the support 101 arealso provided to restrain swiveling of the support 101 from the alignedposition, and these are helpful in keeping the support positioned whenthe boot is being inserted.

The springs acting on the two plungers may be separately adjusted sothat the toe releases more readily by twisting in one direction than inthe other.

It may be noted that this toe binding does not impose any restraint onforwards pivoting of the boot about the toe, when the heel bindingreleases or is about to release.

In operation, the boot 16 is inserted into the bindings by firstlyclosing the locking member 58 into the looking position shown in FIG. 2,and then inserting the toe into the toe binding with the plunger ends106 engaging in recesses 112. The flat end portion 43 of the rod 36 isplaced in position between the projections 51a and 55a of the retainingmeans, and the heel of the boot is then lowered until the cleft 21aengages the rearwards sloping portion 53b of the ridge 53 and causes thetoe of the boot to move forwards and compress the plunger springs sothat the rounded ends of the plungers are held in the recesses 112.Final downwards pressing of the heel causes ball member 45 to snap intothe insert 63, with slight flexing of clip 55.

In this condition, the bindings hold the boot firmly on the ski, whileallowing for very limited movement between the ski and the boot toaccommodate shock loadings on the ski. Thus, the boot can swivelslightly with the toe portion sliding sideways on plate 18, and withresultant swiveling of support 101, providing that the ends of theplungers do not pss beyond the center line ofthe ski. Also, the spring38 allows very slight lifting of the heel from the ski before release ofthe heel takes place. The ankle cuff portion can pivot slightly aboutthe pivots 24, this movement being allowed for by the flexibility of therod 36. The need to bend the rod 36, and to compress or extend thespring 38, imposes resistance on both forward and rearward pivoting ofthe ankle cuff portion, so that the ankle cuff portion is continually,resiliently urged into a neutral position which is chosen so as to bemost desirable for normal skiing. The spring 38 is sufficiently strongto maintain the heel in normal skiing position on the ski (i.e., withthe heel not lifting by more than a very small amount) in the absence ofany other holding means such as conventional heel clamps. In addition,when the skier wants to edge the skis, the bindings ensure that the skirotates with the boot, by virtue of the manner in which the plungers actin the recesses in the toe of the boot, and also by virtue of engagementof the flattened portion 43 of the rod 36 against the inside surfaces ofplate 51 and clip 55. When it desired to remove the skis, the lockingmember 58 is pivoted upwards to an open position, releasing clip 55 andallowing the skier to step out of the binding. Movement of the lockingmember to the open position can be effected by means ofa ski pole thetip of which can be inserted in one of the holes 60a.

If the skier falls forward in such a manner as to cause pivoting of theboot as a whole about the toe through an angle greater than a smallpredetermined angle dependent on the compression in spring 38, the rearbinding will release by the ball member 45 pulling out of the socketformed by the plate 51 and clip 55. This occurs when the rod 36 issubject to extreme forces, which may be a combination of tensile forcesand bending forces urging release of the ball member sideways. Thepredetermined angle by which the boot as a whole can pivot about its toebefore release will be predetermined by reference to known data onsafety release heel bindings, but such angle must be small enough thatin normal skiiing there is no undue lifting of the heel. Release in thisway is similar to that of conventional safety release bindings. Inaddition, however, the rear binding can release in conditions when thedownwards force on the leg opposes the pivotal movement of the boot as awhole to such an extent that an exteme, injury causing bending moment onthe shin bone cannot rotate the boot as a whole through theabove-mentioned predetermined angle. In these circumstances, the bendingmoment on the shin bone causes pivoting of the ankle cuff portion aboutpivots 24 relative to the base portion, and thus causes upwards movementof extension 31 relative to the base portion, increasing the forces inthe rod 36 so that the ball member 45 is released before the shin boneis subject to injury. This pivoting of the ankle cuff portion'willnormally be combined with a tendency to pivot the boot as a whole aboutthe toe, so that release in fact occurs by pivoting of the base portionof the boot about the toe through an angle smaller than theabove-mentioned predetermined angle, combined with forward pivoting ofthe ankle cuff portion relative to the base portion about its pivotalaxis. As

mentioned, the toe release imposes no restraint on this manner of heelrelease, and also allows release on swiveling of the boot about the legaxis, or by an upwards pull on the toe. Release can also occur byrearward pivotal movement, the heel binding releasing after contactoccurs between the lower end of rod portion 43 and the surface 660, asdescribed.

Reference is made in the foregoing and in the claims to the amount ofpivoting of the boot portions which takes place before release, sincethis seems to be the most convenient way of understanding the forcesinvolved. In all heel bindings known to me, it is possible for the heelto lift by a small but definite amount, say between A and *2; of aninch, before the heel is released. However, it will be appreciated thatit is the various forces involved, rather than these angles, which areof primary importance, and the resilient means provided by thecombination of the flexible rod 36 and the coil spring 38 ensure thatthere is a definite relationship between the angles of pivoting and thebending moment applied. Thus, the heel binding is such as to releasewhen subjected to predetermined forces tending either to cause pivotingof the boot as a whole about the toe, or to somewhat lesser forcescausing similar pivoting combined with forces causing pivoting of theankle cuff position on the base portion.

It is anticipated that, unlike with boots and bindings presently usedwhich are made by different manufacturers and fitted together andajusted by shops selling these skis and bindings, the combination of theheel and toe bindings and of the boot will be sold as a single unit.This will mean that the release characteristics of the toe and heelbindings can be adjusted according to the size of the boot, and thenfixed in position at the factory. The release characteristics of theheel binding depend on the stiffness of spring clip 55, which can bereplaced should it be desired to adapt the binding to another skier. Thetwo bindings and the boot may be held together, prior to fitting onto aski, by a thin flexible plastic plate which will act as a template forthe correct positioning and fixing of the bindings on the ski.

The binding of this invention is preferably used with a conventionalsafety strap such as that indicated at 80 in FIG. 1, and which preventsloss of the ski after release.

Various alternatives are possible within the scope of the invention. Inparticular, variations may be made to the shape of the ball member 45and of the insert 63 to give desired release characteristics, and thesemaybe made dependent on the direction of forces on the ball member, forexample by using a non-circular ball member. Specially shaped ball andsocket members may also be designed so that inserting of the ball memberinto the socket member, on stepping into the binding, involves much lessforce than that required to release the ball member from the socketmember by upward pull on the rod. Also, instead ofa hemisphericalprojection on one side only of rod end portion 43, the ball member mayinclude similar projections on both sides of portion 43.

Another possible variation of heel binding within the general scope ofthis invention would be a heel binding of generally conventional type,having a clamping device which grips the base portion of the boot,coupled with a connector between the heel binding and the ankle cuffportion of the boot, the connector interacting with the heel binding insuch manner as to assist release of the heel binding in response toforward pivoting of the ankle cuff portion about the transverse pivotalaxis. Release of the heel binding in response to pivoting of the boot asa whole would of course still occur in the normal manner.

The embodiments of the invention in which an exclusive property orprivilege is claimed are defined as follows:

l. A combined ski boot and binding, comprising:

a boot having a base portion and an ankle cuff portion pivotal on thebase portion about a transverse pivotal axis,

a front binding for releasably holding the toe of said base portion, and

a rear binding for holding the heel of the boot against the ski, saidrear binding including means for releasing the heel in response both topivotal movement of the boot in a vertical plane as a whole about thetoe through a predetermined abnormal angle, and to pivoting of the baseportion of the boot about the toe in said vertical plane portion throughan angle smaller than said predetermined angle combined with a forwardpivoting of the ankle cuff portion relative to the base portion aboutsaid pivotal axis and wherein said rear binding includes resilient meansacting on said ankle cuff portion, said resilient means being arrangedto allow limited forward pivoting of the ankle cuff portion whileincreasing the release forces on the rear binding but allowing the baseportion to remain in firm contact with the ski.

2. The combination of claim 1, wherein said rear binding includeslocating means for the heel which limit rearwards movement of boot, andwherein the front binding comprises a support adapted to be permanentlyattached to the ski by means permitting pivotal movement about avertical axis, said support having two parallel bores spaced apart onopposite sides of said vertical axis, each of said bores carrying aspring loaded plunger having a projecting end, the boot toe beingprovided with two laterally spaced, forwards facing depressions forreceiving the projecting ends of the plungers, the spring loading ofsaid plungers normally holding said projecting ends thereof in thedepressions to hold the toe of the boot in place in normal skiing, theplungers being axially displaceable by an amount sufficient to allow theboot to release by simultaneous sideways swivelling movement of the bootand of the support beyond a position in which a projecting end of aplunger lies directly between said vertical axis and the locating meansfor the heel.

3. The combination of claim 2, also including a slide plate mounted onthe ski in the region of the toe of the boot, and providing a surface onwhich the toe of the boot is slidable sideways.

4. A combined ski boot and binding, comprising:

a boot having a base portion and an ankle cuff portion pivotal on thebase portion about a transverse pivotal axis,

a front binding for releasably holding the toe of said base portion, and

a rear binding for holding the heel of the boot against the ski, saidrear binding including releasable connecting means directly connectingthe ski and a part of the ankle cuff portion behind said pivotal axis,said releasable connecting means being sufficiently deformable to allowsome forward pivotal movement of the cuff portion about said transverseaxis during skiing, and sufficiently resistant to deformationto hold theski in normal skiiing position on the boot during skiing, saidreleasable connecting means being capable of release when excessiveforces are applied thereto either by pivoting of the boot as a whole ina vertical plane about the toe through a predetermined abnormal angle,or by pivoting ofthe base portion of the boot about the toe in saidvertical plane through an angle smaller than said predetermined anglecombined with forward pivoting of the ankle cuff portion relative to thebase portion about said pivotal axis.

5. The combination of claim 4, wherein said transverse pivotalaxis is inthe region of a skiers ankle joint, and wherein said part of the anklecuff portion is a rigid extension projecting from the rear thereof.

6. The combination of claim 4, wherein said releasable connecting meanscomprises releasable retaining means adapted to be permanently attachedto a ski, and deformable connecting means attached to said part of theankle cuff portion behind said pivotal axis and cooperating with saidretaining means in such manner that an extreme forces on said releasableconnecting means releases the deformable connecting means from theretaining means, the resistance to deformation of said retaining meansbeing such that said extreme forces in the deformable connecting meansmay be caused either by pivoting of the boot as a whole about the toethrough a predetermined abnormal angle, or by pivoting of the baseportion of the boot about the toe through an angle smaller than saidpredetermined angle combined with forward pivoting of the ankle cuffportion relative to the base portion about said pivotal axis.

7. The combination of claim 6, wherein said transverse pivotal axis isin the region of a skiers ankle joint, and wherein said part of theankle cuff portion is a rigid extension projecting from the rearthereof.

8. A combined ski boot and binding, comprising:

a boot having a base portion and an ankle cuff portion pivoted to thebase portion about a transverse pivotal axis,

a front binding for releasably holding the toe of said base portion ontoa ski and allowing pivoting of said base portion in a vertical planeforwardly about said toe, and

a rear binding for holding the heel of said boot against the ski, saidrear binding comprising:

a. releasable retaining means adapted to be permanently attached to aski,

b. means projecting rearwardly from the ankle cuff portion and defininga slideway extending generally parallel to the longitudinal axis of thecuff portion, and

c. deformable connecting means comprising in combination a rod havingmeans at its lower end capable of being retained in said retaining meansand having a shaft portion slidable in said slideway and spring meansrestraining downwards movement of said rod relative to said cuffportion, said rod being flexible to allow limited resiliently restrainedpivoting of the cuff portion about said transverse axis both forwardlyand rearwardly of a neutral position, and said spring being sufficientlystiff normally to retain the heel of said base portion in normal skiingposition on the ski, and wherein one or more of the interengaging partsof the rod and the releasable retaining means are resilient wherebyextreme forces in the rod causes release of the rod from the retainingmeans, the resiliency of these interengaging part or parts, and thecompressibility of the spring means and the unstressed length of thespring means being selected so that said extreme forces in the rod maybe caused either by pivoting of the boot as a whole in a vertical planeabout the toe through a predetermined abnormal angle, or by pivoting ofthe base portion of the boot in said vertical plane about the toethrough an angle smaller than said predetermined angle combined withforward pivoting of the ankle cuff portion relative to the base portionabout said pivotal axis.

9. The combination of claim 8, wherein said releasable retaining meansis in the form ofa socket member, and wherein said means at the lowerend of the rod is a ball member engageable with said socket member.

10. The combination of claim 9, wherein the said retaining meansincludes two opposed surfaces spaced from the socket member and facingopposite sides of the ski, and wherein said rod has an extension whichengages between said surfaces and limits sideways angular movement ofthe rod relative to the ski.

ll. The combination of claim 8, wherein the means projecting rearwardlyfrom the ankle cuff portion are spaced upper and lower extensionsthereof each having a bore therein, said bores being aligned so as todefine together said slideway, and wherein said spring means is retainedbetween the upper side of said lower extension and a stop member on saidshaft portion.

12. A ski boot adapted to be used in combination with a ski having afront binding and having part of a rear binding constituted byreleasable retaining means in the form of a socket member, said bootcomprising:

a. a base portion,

b. an ankle-cuff portion pivotal on the base portion about a transversepivotal axis,

0. spaced upper and lower extensions projecting rearwardly from theankle cuff portion and each defining a bore extending generally parallelto the longitudinal axis of the cuff portion, said bores being alignedwith each other, and said lower extension being rigidly attached to theankle cuff portion, and

d. extendible connecting means comprising in com bination a rod having aball member at its lower end capable of being retained by said socketmember and-having a shaft portion slidable in said bores, and springmeans retained between the upper side of said lower extension and a stopmember on said shaft portion, said rod being flexible to allowresiliently restrained pivoting of the cuff portion about saidtransverse axis, and said spring being sufficiently stiff normally toretain the heel of the said base portion in normal skiing position onthe ski when said ball member is in position in said socket member, thecompressibility of the spring means and the unstressed length of springbeing selected in relation to the release characteristics of said balland socket members so that extreme forces in the rod causes release ofthe ball member from the socket member, and so that said extreme forcesmay be caused either by pivoting of the boot as a whole in a verticalplane about the toe through a predetermined angle, or by pivoting of thebase portion of the boot in said vertical plane about the toe through anangle smaller than said predetermined angle combined with forwardpivoting of the ankle cuff portion relative to the base portion aboutsaid pivotal axis.

1. A combined ski boot and binding, comprising: a boot having a baseportion and an ankle cuff portion pivotal on the base portion about atransverse pivotal axis, a front binding for releasably holding the toeof said base portion, and a rear binding for holding the heel of theboot against the ski, said rear binding including means for releasingthe heel in response both to pivotal movement of tHe boot in a verticalplane as a whole about the toe through a predetermined abnormal angle,and to pivoting of the base portion of the boot about the toe in saidvertical plane an angle smaller than said predetermined angle combinedwith a forward pivoting of the ankle cuff portion relative to the baseportion about said pivotal axis and wherein said rear binding includesresilient means acting on said ankle cuff portion, said resilient meansbeing arranged to allow limited forward pivoting of the ankle cuffportion while increasing the release forces on the rear binding butallowing the base portion to remain in firm contact with the ski.
 2. Thecombination of claim 1, wherein said rear binding includes locatingmeans for the heel which limit rearwards movement of boot, and whereinthe front binding comprises a support adapted to be permanently attachedto the ski by means permitting pivotal movement about a vertical axis,said support having two parallel bores spaced apart on opposite sides ofsaid vertical axis, each of said bores carrying a spring loaded plungerhaving a projecting end, the boot toe being provided with two laterallyspaced, forwards facing depressions for receiving the projecting ends ofthe plungers, the spring loading of said plungers normally holding saidprojecting ends thereof in the depressions to hold the toe of the bootin place in normal skiing, the plungers being axially displaceable by anamount sufficient to allow the boot to release by simultaneous sidewaysswivelling movement of the boot and of the support beyond a position inwhich a projecting end of a plunger lies directly between said verticalaxis and the locating means for the heel.
 2. The combination of claim 1,wherein said rear binding includes locating means for the heel whichlimit rearwards movement of boot, and wherein the front bindingcomprises a support adapted to be permanently attached to the ski bymeans permitting pivotal movement about a vertical axis, said supporthaving two parallel bores spaced apart on opposite sides of saidvertical axis, each of said bores carrying a spring loaded plungerhaving a projecting end, the boot toe being provided with two laterallyspaced, forwards facing depressions for receiving the projecting ends ofthe plungers, the spring loading of said plungers normally holding saidprojecting ends thereof in the depressions to hold the toe of the bootin place in normal skiing, the plungers being axially displaceable by anamount sufficient to allow the boot to release by simultaneous sidewaysswivelling movement of the boot and of the support beyond a position inwhich a projecting end of a plunger lies directly between said verticalaxis and the locating means for the heel.
 3. The combination of claim 2,also including a slide plate mounted on the ski in the region of the toeof the boot, and providing a surface on which the toe of the boot isslidable sideways.
 4. A combined ski boot and binding, comprising: aboot having a base portion and an ankle cuff portion pivotal on the baseportion about a transverse pivotal axis, a front binding for releasablyholding the toe of said base portion, and a rear binding for holding theheel of the boot against the ski, said rear binding including releasableconnecting means directly connecting the ski and a part of the anklecuff portion behind said pivotal axis, said releasable connecting meansbeing sufficiently deformable to allow some forward pivotal movement ofthe cuff portion about said transverse axis during skiing, andsufficiently resistant to deformation to hold the ski in normal skiiingposition on the boot during skiing, said releasable connecting meansbeing capable of release when excessive forces are applied theretoeither by pivoting of the boot as a whole in a vertical plane about thetoe through a predetermined abnormal angle, or by pivoting of the baseportion of the boot about the toe in said vertical plane through anangle smaller than said predetermined angle combined with forwardpivoting of the ankle cuff portion relative to the base portion aboutsaid pivotal axis.
 5. The combination of claim 4, wherein saidtransverse pivotal axis is in the region of a skier''s ankle joint, andwherein said part of the ankle cuff portion is a rigid extensionprojecting from the rear thereof.
 6. The combination of claim 4, whereinsaid releasable connecting means comprises releasable retaining meansadapted to be permanently attached to a ski, and deformable connectingmeans attached to said part of the ankle cuff portion behind saidpivotal axis and cooperating with said retaining means in such mannerthat an extreme forces on said releasable connecting means releases thedeformable connecting means from the retaining means, the resistance todeformation of said retaining means being such that said extreme forcesin the deformable connecting means may be caused either by pivoting ofthe boot as a whole about the toe through a predetermined abnormalangle, or by pivoting of the base portion of thE boot about the toethrough an angle smaller than said predetermined angle combined withforward pivoting of the ankle cuff portion relative to the base portionabout said pivotal axis.
 7. The combination of claim 6, wherein saidtransverse pivotal axis is in the region of a skier''s ankle joint, andwherein said part of the ankle cuff portion is a rigid extensionprojecting from the rear thereof.
 8. A combined ski boot and binding,comprising: a boot having a base portion and an ankle cuff portionpivoted to the base portion about a transverse pivotal axis, a frontbinding for releasably holding the toe of said base portion onto a skiand allowing pivoting of said base portion in a vertical plane forwardlyabout said toe, and a rear binding for holding the heel of said bootagainst the ski, said rear binding comprising: a. releasable retainingmeans adapted to be permanently attached to a ski, b. means projectingrearwardly from the ankle cuff portion and defining a slideway extendinggenerally parallel to the longitudinal axis of the cuff portion, and c.deformable connecting means comprising in combination a rod having meansat its lower end capable of being retained in said retaining means andhaving a shaft portion slidable in said slideway and spring meansrestraining downwards movement of said rod relative to said cuffportion, said rod being flexible to allow limited resiliently restrainedpivoting of the cuff portion about said transverse axis both forwardlyand rearwardly of a neutral position, and said spring being sufficientlystiff normally to retain the heel of said base portion in normal skiingposition on the ski, and wherein one or more of the inter-engaging partsof the rod and the releasable retaining means are resilient wherebyextreme forces in the rod causes release of the rod from the retainingmeans, the resiliency of these inter-engaging part or parts, and thecompressibility of the spring means and the unstressed length of thespring means being selected so that said extreme forces in the rod maybe caused either by pivoting of the boot as a whole in a vertical planeabout the toe through a predetermined abnormal angle, or by pivoting ofthe base portion of the boot in said vertical plane about the toethrough an angle smaller than said predetermined angle combined withforward pivoting of the ankle cuff portion relative to the base portionabout said pivotal axis.
 9. The combination of claim 8, wherein saidreleasable retaining means is in the form of a socket member, andwherein said means at the lower end of the rod is a ball memberengageable with said socket member.
 10. The combination of claim 9,wherein the said retaining means includes two opposed surfaces spacedfrom the socket member and facing opposite sides of the ski, and whereinsaid rod has an extension which engages between said surfaces and limitssideways angular movement of the rod relative to the ski.
 11. Thecombination of claim 8, wherein the means projecting rearwardly from theankle cuff portion are spaced upper and lower extensions thereof eachhaving a bore therein, said bores being aligned so as to define togethersaid slideway, and wherein said spring means is retained between theupper side of said lower extension and a stop member on said shaftportion.